. >> reporter: the final segments of the debate will focus on healthcare. >> i want to repeal obamacare and replace it with something to get costs under control. >> reporter: and the role of government. >> reporter: tonight will mark the first of three debates between the two presidential hopefuls this month. as for the two vice- presidential candidates, they will square off in their own debate, michelle, next week. >> all right. so what kind of impact can these debates have on the polls if any? >> reporter: certainly this is a tradition that began 52 years ago. and if history is any indication, there may be some unforgettable moments tonight. certainly i think both candidates are hoping for a spike in the polls based on what happens tonight but more than anything i think they are hopefully as well hoping that they avoid any gaffs which can often times be more memorable than any successful points made at the debate but mitt romney is even specifically mentioning that this will be a critical point in his campaign. this is the first time of you have to think that the two are actually stan